My roommate has had really bad experiences with WinME. And for my part I hate some of the "features" it offers, though I haven't used it on my machine. I find Win98SE runs great, rarely crashes, no compatibilty problems, etc. And I've of the mind if it ain't broke don't fix it, so I have no intent to move to WinME.
Win2000 and Whistler (whistlers not available yet) are a fairly major upgrade over Win9x so you might consider those. But I'm quite happy with Win98SE and so I have no desire to move to WinME not much of an upgrade really.